Parking assistance may be seen as a commodity in certain cases, in particular for passenger vehicles or other light vehicles. But for a growing number of applications, parking assistance has become an essential function. This is particularly the case for the high-precision parking of long vehicles.
There is such a need in particular in intra-port traffic. This traffic comprises moving containers between cargo loading/unloading points and temporary storage areas (connected to the road and rail transport infrastructures). The loading/unloading phases are carried out with the aid of mobile lifting means (cranes) which load/unload the mobile platforms used for transportation between the various points of the port. The precision of positioning of the mobile platform when parking is crucial to accelerating the loading/unloading task and making it safe.
Specifically, the operations of parking a platform or trailer, propelled by means of a motorized cab, are tricky and time consuming, even when they are carried out by experienced drivers. Furthermore, accidents may occur, jeopardizing not only the goods within the containers but also nearby personnel involved in the maneuvers. In order to increase the productivity and safety of port traffic, parking operations must therefore be accelerated while substantially decreasing the number of accidents. In order to decrease these accidents, the containers must be loaded and unloaded with precision, which demands that the platforms be precisely positioned in the parking spaces.
In order to improve precision and make the operations of loading and unloading containers onto/from platforms safe, there exist parking bays equipped with lateral walls. The problem is then to quickly park a platform, trailer or long vehicle in a parking space with a margin of a few centimeters. A parking assistant or automatic parking is necessary for this purpose.
An exemplary application is to manage to get a vehicle that is 13 meters long and 3 meters wide, bearing a payload of the order of 60 tonnes, to automatically insert itself into a parking space with a precision of positioning of the order of centimeters, from a starting position that is about fifteen or more meters away from the parking space, parking area.
Existing solutions use magnetic terminals or the technology referred to as wire guidance. These solutions have multiple drawbacks:
first of all, they require the installation, on the vehicle, of antennas very close to the ground. However, installing elements close to the ground on a vehicle limits its ground clearance and presents a risk to the antennas through impacts with objects located on the ground;
in any case, the antennas must be very precisely positioned horizontally and vertically, as well as in terms of planarity. This is both technically difficult and difficult to guarantee for the long term due to vibrations and impacts, which are inevitable in operational phases;
moreover, devices that are sometimes active, such as transponders or powered metal wires, must be installed in the ground, this requiring substantial work.
These solutions are therefore costly and not very reliable.